ALL VISITORS PLEASE CHECK IN AT FRONT OFFICE, Sign, GENERAL GRAPHIC COMMUNICATION SIGNS - Indicate general instructions relative to safe work practices donít leave people to wander around, wasting time. Restricted areas will not be secure from unauthorized visitors unless everyone knows where they cannot go. Keep your confidential spaces free from unwanted intrusion. One of the easiest ways to accomplish this is with accident prevention signs. A sign gets noticed and helps enforce your policy.